Door for refrigerator compartments



Oct. 16, 1951 A. E. NAVE 2,571,600

DOOR FOR REFRIGERATOR COMPARTMENTS Filed April 1, 1949 3 Sheets-Sheet l v HVVENTUR. ALFRED 5. NA l/E Oct. 16, 1951 A. E. NAVE DOOR FOR REFRIGERATOR COMPARTMENTS 3 Sheets-Sheet 2 Filed April 1, 1949 INVENTOR. ALFRED ENAVE.

Oct. 16, 1951 I A. E. NAVE 2,571,600

DOOR FOR REFRIGERATOR COMPARTMENTSU Filed April l, 1949 AL FRED E. NA 1/5.

A PS.

5 Sheets-Sheet 3 V t Y INVENTOR, m w

Patented Oct. 16, 1951 DOOR FOR REFRIGERATOR COMPARTMEN TS Alfred E. Nave, Cincinnati, Ohio, assignor to Avco Manufacturing Corporation,

Cincinnati, Ohio,

a corporation of Delaware Application April 1, 1949, Serial No. 84,945

4 Claims.

This invention relates Lo refrigerators and particularly to an improved door for a refrigerator evaporator.

In refrigerators of the household type, the interior of the cabinet is commonly cooled by air circulation through convection currents traveling between the relatively warm and cold portions of the interior of the cabinet. The warm air commonly carries moisture therewith which is deposited upon the evaporator in the form of frost. With the adoption of the relatively large horizontal type evaporator which extends substantially from side wall to side wall of the cabinet, conventional evaporator doors have proven unsatisfactory. Because of the relatively large door area and the colder evaporator temperatures maintained by the horizontal type evaporator, conventional evaporator doors such as those formed of metal or glass are subject to unusually large deposits of frost and ice due to increased condensation, which condensation is so excessive as to form icicles on the bottom of the door and under certain extremely humid con ditions of operation causes the door to freeze to the evaporator so that the door cannot be opened until the evaporator has been defrosted. With conventional doors it has been necessary to defrost the door prior to the time that it is normally necessary to defrost the evaporator in order to insure proper cooling of the cabinet even under normal conditions of humidity.

It is accordingly an object of my invention to provide a door for a refrigerator evaporator of such construction as to minimize the formation of frost and ice on the outer surface of the door.

A further object of my invention is to provide a door for a refrigerator evaporator having spaced panels bonded together to form a strong unitary structure sealed against moisture.

Another object of my invention is to provide a door for a refrigerator evaporator formed of two panels of thermoplastic material bonded together by a bonding cement which is a solvent of the basic material in order to insure a homogeneous bond between the panels and one which provides a rigid structure positively sealed against moisture.

These and other objects of my invention will be apparent from the following description and claims, taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a front view of a refrigerator cabinet embodying an evaporator door constructed in accordance with the principles of my invention.

Fig. 2 is a front view of an evaporator door shown in Fig. 1.

Fig. 3 is a plan view partially in section taken along the line 33 of Fig. 2.

Fig. 4 is an end view of the evaporator door with a hinge plate attached to'the door.

Fig. 5 is an end view of the evaporator door shown in Fig. 1 with the mounting plate. removed.

Fig. 6 is a sectional view taken along the line 6-45 of Fig. 2.

Fig. 7 is a front view of the rear panel of the evaporator door illustrating the inner surface of the panel.

Referring to the figures for a detailed explanation of the construction of my improved door, Fig. 1 shows a refrigerator cabinet 9 of conventional construction having a main door I0, and an evaporator door l2, adapted to close off the front opening to a conventional evaporator (not shown) positioned directly behind door 12. The door I2 is mounted to pivot about a horizontal axis to provide access to the evaporator. The cabinet may be cooled by any conventional refrigerating system which does not form a part of my invention.

The improved door constituting my invention is formed of a non-metallic material having good heat insulating properties and preferably is made up from an assembly of two molded panels of thermoplastic material such as, for example, polystyrene. The door 12 includes a molded front panel Ill having an upstanding flange l6 extending about the periphery of the panel and includes a fiat surface I8 at the outer extremity of flange l6 adapted to receive the rear panel 20 of the door. A recess 22 is molded into the front surface of panel l4 and a handle 24 is positioned so that the handle partially overlies the recess. Thus, an open space is provided between the lower extremity of the handle and the lower portion of the recess so that the fingers of a hand may be inserted into the recess to grip the under surface of the handle. In the embodiment shown, handle 24 is formed of metal and includes a pair of laterally spaced hollow studs, indicated at 28, adapted to be inserted into spaced hollow bosses 3B and 32 molded on the inner surface of panel l4 and extending into the interior of the door. The handle is secured to the front panel by similar screws 34 extending through similar washers 38 respectively so as to provide an air tight moisture proof mounting for the handle. Washers 38 are preferably formed of brass but may be of rubber, if desired. Reinforcing ribs 40 are molded on the rear s rface of the door as are a pair of laterally spaced bosses 42, which latter bosses extend rearwardly from the inner surface of panel l4 to the plane of the outer extremity of flange it. Thus, bosses 42 contact the inner surface of the rear panel in the completed door. As shown, flange ii at each side of panel. l4 includes a laterally offset portion 44 and each of said offset portions is provided with three outwardly facing laterally extending hollow bosses normal to the oil'set portion of the flange. These bosses 46, 48 and 50 are molded integrally with the flange and are adapted to receive similar screws 52 for securing a mounting plate 54 at each side of the door. An opening 56 is provided near the bottom of each mounting plate and each opening is adapted to receive a mounting pin about which the door is rotated upon opening and closing of the door. A laterally extending flange 58 at the front of panel l4 at each side of the panel overlies bosses 46, 48 and 50 to conceal them from view.

It will be observed from the construction and arrangement of the front panel l4 just described, that the panel itself is adapted to be mounted for rotation in the cabinet but is impervious to penetration by moisture or air.

The rear panel 20 of the door is likewise molded of material having good heat insulating properties, such as polystyrene and includes a raised rib 52 on the inner surface of the panel extending entirely around the panel. Rib 62 is positioned on panel 20 so as to contact the inner surface of flange IS on panel l4 in order to maintain the panels in a fixed relationship with respect to each other when the panels are assembled. Panel 20 includes an extension 54 extending laterally outwardly beyond rib 62, which extension presents a flat surface adapted to contact surface l8 entirely around the door. A series of raised ribs 55, 65, Ill and H are spaced from rib 62 at each side of the panel 20 and are positioned to have a portion closely adjacent to the outer surface of flange l so that a portion of flange H5 at each side of the door is flrmly gripped between rib 62 and ribs 65, 68, I0 and II when the two panels are assembled. Ribs 65, 68, 10 and H include additional portions l2, 14, and 16 extending normal to the base of the ribs, respectively, and adapted to overlie bosses 45, 48 and 50 respectively. An additional rib 18 at each side of panel extends inwardly to hide ribs 54, 68 and Ill from view when U panel 20 is assembled to panel l4. A plurality of spaced reinforcing ribs 19 are provided on the outer surface of the rear wall of panel 20.

In assembled relationship, panels l4 and 20 enclose a chamber 12 therebetween, which chamber may have suitable insulating material (not shown) such as, for example, rock wool, disposed therein. The panels [4 and 20 are secured-together at surface l8 by coating surface [8 of flange l6 and the surface of panel 20 overlying surface l8 with a suitable solvent of the basic material. The adjacent surfaces are then pressed into contact, and the solvent permitted to dry so that the material again plasticizes, forming a bond at the juncture which is fully as strong as the basic material itself. Thus, the completed door constitutes a monocoque structure which, though formed of two panels of relatively thin molded plastic material is very strong and rigid, being much stronger than either of the component panels of the door. It is also a feature of this construction that the completed door encloses a chamber therein which is completely impervious to infiltration of moisture and air through the joint between the panel sections. It is extremely 4 important that no moisture be permitted to enter the interior of the door, for such moisture would greatly minimize the efficiency of the insulation within the sealed chamber. The solvent used to form the joint between the front and rear panel is preferably a monomer of the basic material, which, as stated, acts as a solvent to soften the material and, upon drying, permits the material to replasticize, forming a seamless joint. A sealed seamless joint may be obtained by the use of a solvent known as Koppers' adhesive for polystyrene.

By this invention I'have provided a molded door for a refrigerator evaporator which is made up of two panels which may quickly and easily be assembled, is very rigid and strong, and one in which the two panels of the door are seamlessly joined together and one in which the closed air space within the door is sealed against inflltration of moisture. It has been found as a matter of experiment that the formation of ice on the outer surface of the door is greatly minimized and practically eliminated even under extremely humid conditions of operation. Due to the homogeneous bond between the two panels, leakage of moisture into the interior of the door is eliminated even after long periods of use. By this construction, freeze up of the door and the formation of icicles on the bottom of the door is eliminated.

What is claimed is:

1. A refrigerator evaporator door comprising a molded front panel, an upstanding flange formed integrally with said panel extending entirely around said panel, a portion of said flange at each side of said panel being offset laterally inwardly from the remainder of said flange, a plurality of hollow bosses formed integrally with said offset portions of said flange at each side of said panel, a mounting plate secured to said bosses at each side of said panel, said mounting plate being substantially flush with and lying substantially in the same plane as the remaining portion of said flange at each side of said panel, an additional flange on the front surface of said panel extending laterally outwardly over said bosses and mounting plate at each side of said panel, a rear panel having a portion thereof disposed in contact relationship with said first-mentioned flange, a rib on said rear panel disposed in contact relation with the side wall of said first-mentioned flange, and a seamless joint between said contact portion of said rear panel and said first-mentioned flange, said front and rear panels enclosing a sealed chamber therebetween.

2. A refrigerator evaporator door comprising a molded front panel, an upstanding flange formed integrally with said panel extending entirely around said panel, a portion of said flange at each side of said panel being offset laterally inwardly from the remainder of said flange, a plurality of hollow bosses formed integrally with said offset portions of said flange at each side of said panel, a mounting plate secured to said bosses at each side of said panel for pivotally supporting the evaporator door, said mounting plates being substantially flush with and lying substantially in the same plane as the remaining portions of said flange at each side of said panel, an additional flange 0n the front surface of said panel extending laterally outwardly over said bosses and mounting plates at each side of said panel, a rear panel having a portion thereof disposed in contact relationship with said first-mentioned flange, a rib on said rear panel disposed in contact relation with the side wall of said first-mentioned flange, and a seamless joint between said contact portion of said rear panel and said first-mentioned flange, said front and rear panels enclosing a sealed chamber therebetween, said front panel being formed to define a centrally disposed recess projecting into the sealed chamber, and a finger grip secured to said front panel and overlying the recess whereby the finger grip may be grasped and the assembled door structure pivoted about said mounting plates.

3. A refrigerator evaporator door comprising a molded front panel, a molded rear panel, a continuous upstanding flange integrally formed with one of said panels projecting towards and engaging the other said panel along a continuous mating face, reinforcing ribs molded into said panels engaging said flange, said front and rear panels being intimately joined by a bonding agent disposed on their mating faces, portions of said flange being laterally offset at the sides of said panels and including bosses formed integrally therewith, said front and rear panels being extended beyond the offset portions of said flange whereby they are hidden from view, and a mountsaid front panel.

ALFRED E. NAVE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,905,853 Grifiiths Apr. 25, 1933 1,947,571 Prince Feb. 20, 1934 2,270,407 Blood et al Jan. 20, 1942 2,378,801 Sidell et a1 June 19, 1945 2,501,540 Ryan Mar. 21, 1950 FOREIGN PATENTS Number Country Date Great Britain Jan. 21, 1941 

